AlCl3-EMIC离子液体中纳米铝粉的制备

为解决纳米铝粉制备能耗大、粒径控制困难、污染严重的问题,在摩尔比为2∶1的氯化铝-氯化-1-乙基-3-甲基咪唑(AlCl₃-EMIC)离子液体中加入二异丁基氢化铝(DIBAL),以液相化学法绿色安全的制备纳米铝粉。采用X射线衍射(XRD)、纳米粒度检测、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X射线能谱(EDS)和线性扫描伏安法(LSV)等方法对纳米铝粉进行表征,并探究其长大过程及反应机理。结果表明,DIBAL浓度为0.25 mol·L^-1、反应时间为0.5 min时获得无团聚且粒径均匀的40～100 nm铝粉,相比其他液相化学法获得粒径更均匀;不同DIBAL浓度下铝粉生长均存在异常长大现象,其原因与Ostwald熟化有关;并且,AlCl₃-EMIC离子液体不仅是反应介质,同时也是纳米铝粉的Al源。     

NC/Al纳米复合含能材料的制备与表征

采用溶胶-凝胶法和超临界二氧化碳干燥法制备了硝化棉/铝粉(NC/Al)纳米复合材料,并通过红外光谱、比表面积、扫描电子显微镜(SEM)以及差示扫描量热(DSC)等分析方法对复合材料进行了表征。研究结果表明: 纳米铝粉与NC气凝胶骨架成功复合; 复合材料为平均孔径在20~50 nm之间的介孔材料,纳米铝粉在凝胶中均匀分散; NC/Al纳米复合材料的比表面积随铝粉添加量增加而下降; 复合材料中纳米铝粉与硝化棉质量比为5∶10时, NC组分分解热由空白NC气凝胶的1689.21 J·g-1提高至2408.07 J·g-1。      

液相化学法制备纳米铝粉及其表征

为了得到微结构可控的纳米铝粉,尝试用液相化学法制备纳米铝粉,并采用X射线衍射(XRD)仪、场发射扫描电子显微镜(FESEM)和能谱仪(EDS)对其进行表征。研究了原料摩尔比、催化剂用量和分解温度对铝粉形貌、粒径和组成的影响。在此基础上,优化出最佳制备工艺参数,当AlCl₃∶LiAlH₄摩尔比为1∶6,催化剂用量为0.04 mL,分解温度为110 ℃时,制得的纳米铝粉为类球形,平均粒径约为50 nm,杂质Cl、Ti含量少。     

纳米邻苯二甲酸铅的制备及其对双基推进剂燃烧催化的研究

以邻苯二甲酸氢钾和乙酸铅为原料,采用超声液相分散沉淀法制备了纳米邻苯二甲酸铅粉体。研究了反应温度、反应物浓度以及分散剂用量对配合物粒径的影响。在反应物浓度为0.4mol·L-1、反应温度为10℃、分散剂用量为8%(v/v)时,制得平均粒径为43nm的纳米邻苯二甲酸铅。通过研究纳米邻苯二甲酸铅对双基推进剂燃烧的催化作用,发现纳米邻苯二甲酸铅在2～22MPa范围内能提高双基推进剂的燃速,且使双基推进剂在6～10MPa范围内出现较强的麦撒燃烧效应。与普通邻苯二甲酸铅催化剂相比,纳米邻苯二甲酸铅使双基推进剂燃速高于含普通邻苯二甲酸铅的双基推进剂的燃速,且在6～10MPa范围内压力指数更低。     

粒径大小对高频感应加热制备纳米铝粉活性影响

采用高频感应加热蒸发-冷凝法制备了20,25,50 nm三种不同粒度的纳米铝粉,并运用X射线衍射(XRD)和透射电镜(TEM)对纳米铝粉进行表征,使用差热分析(DTA)研究了不同粒径纳米铝粉的热学行为。结果发现,随着纳米粒子粒径从50 nm减小到20 nm,纳米铝粉反应放热热焓从3.721 kJ.g-1减少到0.928 kJ.g-1,即随着粒径的减小纳米铝粉的活性反而变低。认为这是由于铝纳米粒子表面氧化铝膜含量的增加,采用高频感应加热方法制备的粒子不存在内部储能所致。因此,纳米铝粉的活性,不仅取决于粒子的尺寸大小,还取决于粒子的制备方法,以及粒子表面包覆壳层的种类、结构、厚度等。     

Cu/Al复合材料的制备及其对RDX热分解性能的影响

为了改善铝粉的表面氧化,提高其对含能材料热分解的催化作用,以电爆炸铝粉和二水合氯化铜(CuCl_2·2H_2O)为原料,利用置换反应法,实现了纳米铜粒子在铝粉表面的快速沉积,制备了包覆均匀的Cu/Al复合材料。利用扫描电镜(SEM)、透射电镜(TEM)、X?射线粉末衍射(XRD)、电子能谱(EDS)等对其结构和形貌进行了表征。在不同的升温速率下测试了Cu/Al复合材料与黑索今(RDX)(质量比1∶5)混合物的DSC曲线。计算了该混合物热分解反应的动力学参数。结果表明,电爆炸铝粉表面的氧化层通过氟化铵的刻蚀作用被剥离,复合材料含有单质铝和单质铜晶相,无氧化铜及氧化铝晶相,纳米级铜颗粒均匀包覆在铝粉表面,复合材料粒径为200～500 nm。加入Cu/Al复合材料后,RDX的初始分解温度和分解峰温分别降低8.51℃和26.43℃,分解热提高296 J·g~(-1),热分解活化能降低19.19 kJ·mol~(-1),表明Cu/Al复合材料可促进RDX的热分解行为。     

Al-Cu复合金属粉的电爆炸制备及其反应活性

为进一步提高亚微米铝粉的反应活性,采用复合金属丝电爆炸技术制备了Al?Cu复合金属粉,通过罗氏线圈监测了电爆炸过程中的波形图,确定制备工艺参数.采用X射线粉末衍射(XRD),扫描电子显微镜(SEM),透射电镜电子能谱成像分析(TEM?MAPPING),X射线电子能谱(XPS)等表征手段完成了对材料结构的分析,Al?Cu复合金属粉主要由CuAl2与Al组成,形貌为光滑球形,平均粒度为150 nm,分析了材料结构的形成机理.分别采用DSC法与铝?水蒸气反应法评价了材料的反应活性,DSC测试结果表明Al?Cu复合金属粉初始氧化峰温为550℃,与同样条件下制备的铝粉相比降低了50℃,反应活性明显提高;初始氧化过程温度跨度由500～650℃变为500～600℃,初始氧化过程的时间由7.5 min缩短到5 min,放热反应速率提升了33％.水蒸气反应评价结果表明,Al?Cu复合金属粉和Al粉的反应完全度分别为0.88和0.73,在反应初始阶段(0～10 min)Al?Cu复合金属粉反应完全度数值达到0.36,是铝粉反应完全度的10倍,与铝粉相比Al?Cu复合金属粉的反应活性与反应完全性大幅提高.     

纳米CuO的制备及其在微孔装药中的应用

采用常温固相反应法在聚乙二醇2000作为分散剂条件下制备了纳米Cu O,用超声共混法制备了纳米Al/Cu O。借助X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等方法对所制备样品的性能进行表征和分析。结果表明:制备的纳米Cu O结构形貌统一,类似八面体结构,一次粒径在30nm左右,和球形的纳米Al粉混合均匀,形成纳米Al/Cu O,团聚后在100~200nm之间,差热分析(DTA)其放热量为2 798J·g-1。将纳米Al/Cu O配制成含能油墨,用喷墨打印装置实现了药室直径为0.7mm、厚度为1mm的10×10阵列装药,并研究了纳米Al/Cu O在微孔装药中的应用。结果表明,纳米Al/Cu O在微孔中能稳定燃烧,燃烧时间在微秒级,火焰长度约为2~4cm,燃速约为0.142 9m/s。     

纳米Al/PS微胶囊中铝粉含量及活性分析

采用优化的工艺条件,制备了不同铝粉含量的纳米铝粉/聚苯乙烯(Al/PS)微胶囊,随着铝粉添加量的增加,铝粉的包覆率逐渐降低。纳米Al/PS微胶囊呈球形,表面光滑无明显缺陷,粒子与粒子之间分散性很好。对纳米铝粉复合前后的活性变化进行了实验分析,结果表明,不同纳米铝粉含量的纳米Al/PS微胶囊中的活性铝含量基本相同,未经贮存、自然条件下密闭贮存30 d及氧气罐中贮存30 d后,活性铝含量分别为76.07%,76.06%和74.81%,纳米铝粉被PS包覆后可长期保持活性。     

喷雾干燥技术细化NTO及其性能

为改善3-硝基^-1,2,4-三唑-5-酮(NTO)的形貌及减小粒径,以丙酮为溶剂,采用喷雾干燥技术制备得到细化NTO产品,研究了入口温度,进气流量,进料速率,前驱液质量浓度对细化NTO形貌及粒径的影响,筛选出最佳的喷雾干燥工艺参数;利用扫描电镜(SEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)和同步热分析仪(TG-DSC)对细化NTO产品的表面形貌、分子结构及热稳定性进行了表征与测试。结果表明,在入口温度为60℃,进气流量为357 L·h^-1,进料速率为3 mL·min^-1,NTO前驱液浓度为16.57 mg·mL^-1时,可获得形貌效果好、晶体结构稳定、粒径分布范围较窄且平均粒径为1.2μm的类球形NTO;与原料相比,细化NTO的热分解表观活化能提升了41.7 kJ·mol^-1,热爆炸临界温度提高了10.4℃,具有更优的热稳定性。     

Nitrosation and Nitration of Tetraacetyldibenzylhexaazaisowurtzitane

Tetraacetyldibenzylhitane (TADBIW) was subjected to debenzylation by nitrosating with inorganic materials available commercially to synthesize tetraacetyldinitrosohexaazaisowurtzitane (TADNSIW). TADNSIW was purified, and its structure was determined by FTIR, 1H NMR, MS and element analysis. The debenzylation reaction of TADBIW gave quantitative benzaldehyde as a by-product. This indicates that the reaction produces an imine cation as an intermediate. Hexanitrohexaazaisowurtzitane (HNIW) was prepared from unpurified TADNSIW with the yield over 96.0 % and the purity more than 98.0 %. And the mechanism of the reaction from TADNSIW to HNIW is proposed to be oxidation of nitroso and nitration of acetyl on the molecule of TADNSIW, This reaction system involved is simple, and the reaction can complete within a short time and under mild conditions. The product can be easily to separate and the waste disposed readily.     

A Robust Algorithm for Watermarking 2D Vector Maps with Low Shape-Distortions

The technique of watermarking has been introduced into 2D vector maps for many potential applications such as protecting the copyright of important GIS （geographical information system） data and tracing the data source of military maps. In most previous works, although the validity of the map data could be preserved during the embedding procedure, the shape-distortions of the map elements are usually neglected which would tend to degrade the invisibility of the watermarking schemes. A shape-preserving algorithm for watermarking 2D vector maps is presented in this paper. A 1D distance sequence extracted from the original map is adopted as the cover data instead of 2D coordinates. A watermark bit is represented by changing the distributions of the cover data. The embedding procedure induces lower shape-distortions than in former works. Experimental results indicate better invisibility of the proposed scheme, as well as its robustness to certain attacks such as map simplification, interpolation, additive noise and most geometric transforms.     

Open Rule-setting System Applied to Conceptual Design of Engines

Open rule-setting method advanced in this paper concentrates on providing designers of engines with a convenient way to express their design innovations and develop the expected prototypes in the early CAD stage, and constitute effective models for the following analysis process of CAE and CAPP. The problems arisen in the process of conceptual design with the traditional experience-based development method are analyzed. Based on those analyses, open rule-setting method is presented and some associated technical problems are discussed. The functional framework of open rule-setting system was built as software engineering methods. The speciality of the engine product as a kind of complex product and the requirement of the engine product based on its structural particularity to rule-setting system are considered carefully. A demonstration is supplied to illustrate how the open rule-setting method enhances the efficiency and quality of the engine conceptual design.     

Research on Linux Network Device Driver

By analyzing the working principle of Linux network device driver, discussing the Linux network driver structure and its key technologies, the general network driver structure and its design methodologies in Linux system are summarized. Through modifying the network device driver of Linux device driver 3rd version snull, c and improving the COW technology, the Zero-Copy technology in Linux （kernel version 2.6.11 ） is implemented. In the end, the success test tells us that the thorough analysis of network device driver is the foundation of many applications, and it also provides a certain improvement to a lot of real applications, even to military application development.     

Improvement and Experiment of the Reamer in Vibra Cutter Against Wave Edge of Titanium Sheet Alloy Parts

By analyzing the influencing factors of part quality making of sheet alloy of titanium by vibra cutter, the shape of upper reamer is set as cylinder and wedge-shaped form, and the lower reamer as plain and hemicycle form, and its main structural parameters are defined as well. Then it is validated further that such improved vibra cutter reamer can be used to process curve-edged parts of titanium alloy sheet. The experimental result shows that the titanium alloy sheet parts processed by above equipment have no sharpen angles for convex parts and evident crevasse of concave-edged part. In summary, such improvement can eliminate the free-waved edge and improve the manufacture quality of titanium alloy sheet parts greatly.     

Algorithm for Multi-laser-target Tracking Based on Clustering Fusion

Multi-laser-target tracking is an important subject in the field of signal processing of laser warners. A clustering method is applied to the measurement of laser warner, and the space-time fusion for measurements in the same cluster is accomplished. Real-time tracking of multi-laser-target and real-time picking of multi-laser-signal are introduced using data fusion of the measurements. A prototype device of the algorithm is built up. The results of experiments show that the algorithm is very effective.     

Experimental Study on the Small Flyer Initiating Behavior of Fine-grained Explosives

The initiating behavior of fine-grained explosives by small flyer is studied. The diameter of small flyer in this device is 1 ram. The test results indicate that the granularity of explosives has great effect on its flyer initiating sensitivity.The flyer initiating sensitivity of the fine-grained explosives is higher and the critical initiating energy is lower than that of common explosives. For common explosive, the flyer initiating sensitivity increases as the density is reduced. But for the fine-grained explosive, the test results are exactly opposite.     

Influence of Installing Error on the Surface Shape Precision of the Axial Symmetry Aspheric Workpiece in Lapping

A method to calculate the surface shape error, which is caused by the installing error between the workpiece and the lapping tool in the process of form lapping, is proposed. The mathematical model which the installing translation error influences on the workpiece surface shape error is established. The changing rule of the error is simulated through the calculating example of the paraboloid workpiece. The results indicate that the surface shape error of the workpiece is increasing with the increase of the installing translation error, it is also increasing gradually along the center point of the curve surface to the edge, and the influence is severer to the curve surface with great curvature than that of the small curvature when the translation error is the same.     

Experimental Research on Output Performances of Giant Magnetostrictive Actuator

The paper introduces the performances of magnetostrictive actuators and its applications, discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator, and makes tests on the output displacement and force characteristics for an actuator using homemade magnetostrictive material. The experimental result shows that the actuator has satisfactory output precisions and ranges in transient and stable states, and can be used in lowfrequency vibration control system of precise equipment.     

Robust Graded Sliding Mode Tracking Control for Low Speed Spinning Ballistic Missiles

The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent ＂explosion of terms＂. Owing to the upper bounds of the uncertainties are difficult to obtain in advance, adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.